When you upload a video to YouTube, you'll see a rapid-fire assortment of thumbnails from the video after it begins uploading to the site. Aside from being fun to watch (it's kind of like a flipbook of your video!), this visual representation of the process gives you further peace of mind that the video is indeed processing and will soon be live on the site. Shortly after the last thumbnail arrives, your video is ready for viewing and sharing.* If you see the flipbook soon after you begin uploading, this means your video will be processed faster and you won't have to wait long for your video link. If you're uploading in the .mov or .mp4 (aka Quicktime) format, and you produced your video using Final Cut Pro, iMovie or QuicktimePro, learn how to optimize your files. By ensuring the "index" of your file is in front, we can process your video faster. This is referred to by some as "flattening" a file or creating a "fast start" video file. If you're using FLV, ASF or WMV formats, you're fine. If you're using AVI, we'd want that index in front of the file as well. Most digital cameras producing AVI or MVI formats are fine.